Login screen freezes

New Member

My screen freezes when the login screen is loaded, but the computer does not freeze, because I can type in my password (I can't see the dots though) and hit ENTER, then it logs in, but the screen turns into one big mess after that. If I click the power button on my computer it hibernates. When turn the computer on after a hibernate, everything works as it supposed to do. The screen only freezes after a shutdown. The computer seems to be having a hard time running heavy graphics lately.

I made a clean Windows 7 install for about 6 months ago and I haven't used the computer much since then.